Apparatus for vibrating seats

ABSTRACT

A driver&#39;s seat having a vibration generator connected to the driver&#39;s seat and controls for turning the vibration generator on and off for vibrating the driver&#39;s seat so that when a driver feels drowsiness coming on, the driver can operate the controls for switching on-off the vibration generator so that the driver&#39;s seat can be vibrated and prevent the driver from dozing during driving and prevent an accident from occurring.

This application is a continuation of application Ser. No. 08/358,248filed Dec. 19, 1994, now abandoned, which is a divisional application ofSer. No. 08/194,356 filed on Feb. 10, 1994, now abandoned, which is acontinuation-in-part application of Ser. No. 07/987,481 filed Dec. 4,1992, now U.S. Pat. No. 5,348,370.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus used for vibrating a driver's seatof automobiles, or the like in order to keep a driver alert and toprevent a driver from dozing during driving.

2. Description of the Relevant Art

A variety of apparatus have been proposed to keep a driver alert and toprevent a driver of automobiles or the like, from dozing during driving.Such apparatuses usually comprise a sensor for sensing that a driver hasstarted to doze and means for alerting or wakening a driver by receivinga signal from a sensor. For example, there is a sensor which senses thata driver has started to doze by sensing the number of times the drivernods per unit time or the time for leaning one's head forward, and thelike, because a driver nods when the driver starts to doze, and sends asignal to means for alerting the driver. Also, there are means foralerting a driver which operates by receiving the signal, and alertingthe driver by producing a loud sound in the driver's ear or ears.Therefore, according to this apparatus, if a driver starts to doze, thesensor senses that the driver's head is leaning forward, and actuatesthe means for alerting or waking up the driver.

However, because the above mentioned apparatus operates only after adriver has started to doze off, the driver may lose concentration, dueto drowsiness, when the driver has started to doze, to such a degreethat the means for alerting and waking up the driver may not beeffective.

Accordingly, the objective of this invention is to provide apparatus forpreventing a driver from dozing off by vibrating the seat.

SUMMARY OF THE INVENTION

In order to accomplish the above objective, the apparatus of thisinvention for vibrating seats comprises a driver's seat and means forvibrating such driver's seat and means for controlling the vibration ofsuch means for vibrating the driver's seat.

As a result of a series of studies of apparatus to effectively preventdozing during driving, the inventors have discovered that it is too lateto prevent accidents when a driver is awaken by a sensor that senses adriver has started to doze. The inventor has discovered that, if adriver's seat is always being vibrated, the driver remains alert, cannotdoze off and, as a result, traffic accidents caused by dozing duringdriving can be completely prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully described and will be better understoodfrom the following descriptions, taken with the appended drawings, inwhich:

FIG. 1 is a side view of one embodiment of the present invention;

FIG. 2 is a top plan view of the apparatus of FIG. 1 with the driver'sseat removed;

FIG. 3 is a side schematic view of an automobile incorporating theinvention of FIG. 1;

FIG. 4 is a vertical sectional view of the vibrator of this embodiment;

FIG. 5 is an enlarged view, partly in section, of the apparatus of FIG.1;

FIG. 6 is a top view of the driver's seat and the control panel forcontrol of the apparatus of FIG. 1;

FIG. 7 is a rear view of the apparatus of FIG. 6;

FIG. 8 is a side view, similar to FIG. 1, but showing another embodimentof the invention;

FIG. 9 is a front view, partly in section, of the vibrator arrangementof the embodiment of FIG. 8;

FIG. 10 is a side view, similar to FIG. 8, but showing a still furtherembodiment of the invention;

FIG. 11 is a front view, partly in section of the embodiment of FIG. 10;

FIG. 12 is a side view, similar to FIG. 10, showing yet anotherembodiment;

FIG. 13 is a rear view of the embodiment in FIG. 12;

FIG. 14 is a side view, partly in section, of still yet anotherembodiment;

FIG. 15 is a rear view of the embodiment of FIG. 14;

FIG. 16 is a side view, partly in section, of still a furtherembodiment, of the invention;

FIG. 17 is a side view, partly in section, of the embodiment of FIG. 16,with the apparatus in a different position;

FIG. 18 is a side view, partly in section, of a further stillembodiment, similar to FIG. 16;

FIG. 19 is a side view of the apparatus of FIG. 18 with such apparatusin a different position;

FIG. 20 is a side view, partly in section, of still another embodimentof the invention;

FIG. 21 is a side view, similar to FIG. 20, but with the apparatus in adifferent position; and

FIG. 22 is a side diagrammatic view, of a still further embodiment ofthe apparatus of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following are detailed descriptions of the various embodiments.

FIG. 1 shows a side view of the first embodiment of the invention,having a structure for vibrating a driver's seat 1 by a motor 10installed on the underside of the driver's seat whereby the vibration istransmitted to the driver's seat 1 when the vibration motor 10 isactivated. Driver's seat 1 is mounted on base 2 and, as best shown inFIG. 2, is attached to base 2 by angle fasteners 3 shaped like an L, andwhich face each other, at a position toward the front and a rear end ofbase 2. Stationary plates 1a, are fixed, by bolts 4, on the radialoutward slants of said angle fasteners 3 at the front end and the rearend of the base of seat 1. The other side of angle fasteners 3 arewelded on the upper side of base 2. Vibration motor 10 is fixed withbolts 5 on the underside of base 2. Output shaft 10a of vibration motor10 extends in a horizontal direction, as viewed from the front of thedriver's seat 1 and from the front of automobile 15 shown in FIG. 3. Asshown in FIG. 4, eccentric loads 13, comprising fixed load 13a and anadjustable load 13b, are installed on opposite ends 10b of output shaft10a, the direction of rotation being indicated by an arrow in FIG. 1 ofvibration motor 10. The centrifugal force caused by eccentric loads 13,rotating at the opposite ends of output shaft 10a, causes base 2, andseat 1 mounted thereon, to vibrate. In FIG. 4, 10c is a stator core and10d is a rotor core of vibration motor 10 which is an electric motor.

Base 2, with supporting seat 1 thereon is elastically supported by itscorner, FIG. 2, on bed 6. Bed 6 is fixed on the floor 16 of anautomobile 15, FIG. 3. Hollow rectangular barrel frames 7 (shown inFIGS. 1 and 2), having frame bodies 7a and 7b (see FIG. 5), are weldedtogether on the front and rear on the upperside of bed 6. Springsupports 8 are installed on the right and left (see FIGS. 1 and 5);front and rear (see FIG. 2), of the upperside portion of rectangularbarrel frames 7. Each of the springs supports 8 includes a disc typebottom parts 8a, support parts 8b installed on the middle of theupperside of disc type bottom parts 8a, and passenger 8c penetratingboth bottom parts 8a and support parts 8b. Bottom parts 8a are fixed onthe upperside of rectangular barrels 7 with screws 9. Support parts 8bare engaged, from the outside, with springs 11. Bolts 12 are insertedthrough each passage 8c. Each bolt 12 is inserted from the uppersideinto each bolt hole 2a, on base seat 2. The nut screw part of each bolt12 is fixed, for example, by welding on the ceiling of each rectangularbarrel 7. Thus, the underside of the base 2 for installation of seat 1is elastically suspended on the upper end of springs 11.

In an automobile 15, showing a FIG. 3, controller console panel 14 isset up on the right side, facing forward, of the driver's seat 1, asshown in FIGS. 6 and 7. Arranged on the console panel 14 are power-onswitch 14a, power-off switch 14b, operation switch 14c, and frequencyhandle 14d for enabling the speed and the number of vibration frequencyof vibration motor 10 to be varied and set at a desired frequency.Further arranged on the console panel is a timer 14e for setting a timerfor start-up and stopping of vibration motor 10 and seat vibrationcaused thereby; are arranged. Controller console panel 14 also containsan inverter (not shown) so that an electric current from a battery 17installed in the front part of an automobile 15 is converted intoalternating current for supply to the vibration motor 10. In this firstembodiment, the apparatus can provide the driver's seat, having amaximum unload of 100 kgs., with 20 Hz in the number of vibrationfrequency and 15 mm of the amplitude of the vibration for vibrating thedriver's seat 1 up-down and back-forth.

When the driver feels drowsiness coming on, the driver can turn onpower-on-switch 14a and then turn on operation-switch 14c so thatvibration motor 10 operates during a period set up with timer 14e,generates vibration and such vibration is transmitted through base 2 todriver's seat 1 through fasteners 3 and stationary plate 1a to driver'sseat 1 and driver's seat 1 vibrates on springs 11. The vibrating driverseat 1, with the above-described structural arrangement and operation,the driver alert and wards off dozing of the driver during driving.

In FIGS. 8 and 9, a modification of the embodiment of FIGS. 17 is shownand will now be described. In this second embodiment, a pulley base 22is set up on the underside of the base 2. Vibration motor 10 is fixed bybolts 23, on the underside of the pulley base 22. Rubber vibrationinsulators 24, covering bolts 23 are fixed between the upperside ofsupport 10b of vibration motor 10 and the underside of pulley base 22.Power transmission shaft 25, on which pulley 26 is mounted, is installedhorizontally between left wall 22a and right wall 22b of pulley base 22,under driver's seat 1, and is connected by belt 21 to pulley 20 mountedon output shaft 10a of vibration motor 10. Support parts 27, as shown inFIG. 8, are provided on the bed 6, whereby the driver's seat iselastically suspended through rubber vibration insulators 28. Parts,except for those described above, are the same as those in the firstembodiment and the same numbering is adopted. In FIG. 9, 29 and 30 arebearings.

According to this second embodiment, vibration generated by vibrationmotor 10 is transmitted mainly through lower pulley 20 and belt 21 tothe upper pulley 26, and further from upper pulley 26 through powertransmission shaft 25 to the base 2 for the driver's seat 1, and so on.

Rubber vibration insulators 24 on the pulley base 22, vibration motor10, reduce troubles caused by vibration.

FIGS. 10 and 11 show a third embodiment of the invention similar to thefirst and second embodiments. In such third embodiment, a motor 32 isinstalled on the underside of receiving the pulley base 22 and aneccentric load 34 is fixed on power transmission shaft 33 supported forrotation on walls 22a (left) and 22b (right) of pulley base 22. Theother parts in the embodiment are the same reference as those of thesecond embodiment and the same numbering is adopted.

According to this third embodiment, when the rotation of the motor 32 istransmitted through output shaft 32a of motor 32, pulley 20 and belt 21to pulley 26 and power transmission 33, eccentric load 34 on powertransmission 33 vibrates and such vibration is transmitted to base 2 ofdriver's seat 1. In this third embodiment, motor 32, itself, does notvibrate and the durability of the motor 32 is drastically improved.

In the above first through third embodiments, the power transmissionshafts of the vibration motor and pulley shafts extend in a directionthat is tranverse to the direction of travel of the vehicle 15, FIG. 3.However, this is not intended as limiting in scope and also each of themcan be installed in the same direction as the direction of travel of thevehicle 15.

Also, in the above first through third embodiments, a bed 6 is fixed onthe floor 16 of vehicle 15. This is also intended not as limiting inscope and the base 6 may be fixed on the floor 16 slidably in back andforth directions.

FIGS. 12 and 13 show a fourth embodiment of the invention. In suchfourth embodiment, a U-shaped flat spring 42 is installed between adriver's seat 1 and a base 38 and an electro-magnet 43 is connected toone of the ends 42a and 42b of the flat spring 42, while a permanentmagnet 44 is connected to the other ones of the ends 42a and 42b.Vibration of spring 42 is generated by sending electrical current intoelectro-magnet 43 and such vibration is transmitted to the driver's seat1 so that the driver's seat 1 vibrates. In detail, an upper vibratingbody 40 is fixed under the driver's seat 1 and a concave part 40a isformed in the middle on the underside of said vibrating body 40.Additionally, the lower vibrating body 41 is fixed on the upperside ofthe base 38 by bolts 47, and a rubber vibration insulator 48, whichcovers bolts 47, is fixed between the upperside of the base 38 and theunderside of lower vibrating body 41. A concave part 41a is formed inthe middle on the upperside of vibrating body 41. A U-shaped flat spring42 is mounted between concave parts 40a and 41a. Height-adjustable bolt39 is adjustable to fix the height of base 38 on the floor 16 ofautomobile 15, as shown in FIG. 3.

The underside of lower end 42a of flat spring 42 is welded to the bottomface of concave part 41a of lower vibrating body 41, while the uppersideof upper end 42b of flat spring 42 is welded on the upperside of concavepart 40a of upper vibrating body 40. An electro-magnet 43, having afixed iron core 46 wound with coil 45, is fixed on the upperside oflower bar 42a of flat spring 42, while a moving iron core 44 is fixed onthe underside of the upper bar 42b. Support board 48 is fixed on theside part of lower vibrating part 41 by a bolt 49. Controller 50 isfixed on support board 48 by a bolt 51. Controller 50 similarly containsan inverter, same as in the electric current adjustable handle 51a, orthe like, and controlling alternating current supplied to coil 45 areinstalled on console panel set up in the rear side of controller 50.

As shown in FIG. 13, lower vibrating body 41 and upper vibrating body 40are connected, at opposite right and left sides, by flat spring 52.Thus, the upper part of flat spring 52 is fixed on the upper stay 55 andfixed on said upper vibrating body 40 by bolts 54, while the lower partof flat spring 52 is fixed on the lower say 58, fixed on the lowervibrating body 41 by bolts 57. In such a fixed state, flat spring 52 istilted toward the rear, as shown in a chain line of FIG. 12, so that itworks to set resonance frequency. In the third embodiment, 100 kgs. fora seat maximum load, 20 Hz for number of vibration frequency and 15 mmvibration for amplitude (i.e., vertical vibration of the driver's seat 1such that its vibration is slightly tilted in a backward direction) aregiven to the driver's seat 1.

In the fourth embodiment, if a driver feels drowsiness coming on, thedriver can turn on power-on switch and then operate an electric currentadjustable handle 51a, installed on a console panel, so that suitablealternating current is sent to a coil 45 of electro-magnet 43. Becausemagnetic flux is generated on fixed iron core 46 of the electro-magnet43, moving iron core 44 is attracted toward fixed iron core 46 and therear part of upper vibration body 40 is tilted downward. When thealternating current becomes zero, the attracting force becomes zero andat the moving iron core 44 is returned to the original position byelastic stress of flat spring 42. In addition, both flat springs 42installed between opposite sides of lower vibrating body 41 (left) andsaid upper vibrating body 40 (right) establish resonance frequencytrailing the movement of upper vibration body 40. Thus, lower vibratingbody 41 and upper vibrating body 40 vibrate vertically (in a directiontilted backward a little), and such vibration is transmitted, throughupper vibrating body 40, to the driver's seat 1. A driver seated in thedriver's seat 1 is kept alert by the vibration of the driver's seat andis not liable to doze off during driving.

FIGS. 14 and 15 show a fifth embodiment. In the fifth embodiment, agroove 41b is formed on the bottom face of the concave part 41a of lowervibration body 41 and the lower end of compression coil spring 60 ispositioned in groove 41b and fixed. Groove 40b is formed on theupperside of the concave part 40a of upper vibration body 40, and theupper end of said compression coil spring 60 is positioned in groove 40band fixed. Electro-magnet 43 is fixed on the bottom face of concave part41a of lower vibration body 41 inside of compression coil spring 60.Moving iron core 44 is fixed on the upperside of the concave part 40a ofthe upper vibration body 40 inside the compression coil spring 60. Asshown in FIG. 15, lower vibration body 41 and upper vibration body 40are connected with flat spring 61 at its opposite right and left ends ofbody 41. One end of flat spring 61 is fixed by a bolt 62 on a lower stay64 fixed on lower vibration body 41 by a bolt 63, while the other end isfixed by a bolt 65 on the upper stay 67, which fixed on upper vibrationbody 40 by bolt 66. Flat spring 61, in such a fixed state and in ahorizontal position, as shown by a chain line of FIG. 14, operates so asto set resonance frequency. Mainly in this fifth embodiment, a verticalvibration is provided to the driver's seat. The other parts, except forthe above, are the same as those of the fourth embodiment and the samereference numbering is adopted.

In the above fourth and fifth embodiments, electro-magnet 43 is used forthe lower vibration body 41 and a moving iron core 44 is used for theupper vibration body 40. This, however, is intended not as limiting inscope; and it is possible that electro-magnet 43 is used for the uppervibration body 40 and a moving iron core 44 can be used for the lowervibration body 41.

In the sixth embodiment of FIG. 16, a pneumatic cylinder vibratesdriver's seat 1. A pneumatic cylinder 70, having an upper wall 71a, hasa rod 72 passing through in rod hole 71b, formed on the middle part ofan upperside 71a of cylinder body 71. The driver's seat 1 is fixed onthe upper end of rod 72, while piston 73 is fixed on the lower end.Piston 73 is slidable, vertically, in cylinder chamber 74, the pistondividing cylinder chamber 74 into an upper chamber 75 and a lowerchamber 76. A spring 77 is arranged between the concave part of theupper side 71a of cylinder body 71 and the concave part of the uppersideof the piston 73, and piston 73 is pressed downward by energy of spring77. A line 78 is extended from lower chamber 76 and connected to achannel control valve 80.

In channel control valve 80, a valve rod 82 is slidably arranged insidea casing 81 and an iron core, or permanent magnet 83, is installed atthe left end of the valve rod 82. A maximum diameter part 82a is formedin valve rod 82, dividing the casing 81 into two parts, a right chamber84 and a left chamber 85. Electro-magnet 86 is fixed on a part of thehousing of control valve 80 to the right from the left end by a definitedistance on the chamber 85, while air-supply line 88, extended from acompressor 87, is connected to chamber 85. Spring 89 is positioned inright chamber 84 and valve rod 82 is pressed toward the left, FIG. 16,by energy of the spring 89. A passage 90 to atmosphere leads from rightchamber 84 to the atmosphere outside.

Electro-magnet 86 is electrically connected, through an inverter, with abattery 17 of an automobile 15 such as in the fourth embodiment.Moreover an on-off switch for vibration, which controls the supply ofelectricity to electro-magnet 86, is arranged on a console panel 18 ofan automobile 15, FIG. 3. When the switch for vibration is pushed, theelectro-magnet 86 is charged with alternating current.

In this embodiment, as shown in FIG. 16, in normal condition thevibration switch is not pushed and electro-magnet 86 is not charged withelectricity and magnetic force is not generated in the electro-magnet86. The valve rod 82 is pushed to the left by elastic energy of spring89 and contacts the leftside of a casing 81, wherein the maximumdiameter part 82a of valve rod 82 is positioned between the connectedline 78 and air supply line 88. Thereby, connected line 78 and passageto the atmosphere 90 are connected through the right chamber 84, whilethe communication of a line 78 and air supply line 88 are cut off by themaximum diameter part 82a. Therefore, the air of lower chamber 76 isconnected to the atmosphere so that piston 73 is pressed downwardlytoward a downside of the cylinder 71 by elastic energy of the spring 89and the driver's seat 1 is supported by the upper wall 71a of cylinderbody 71. In this case, the air from a compressor body 87 is released tothe atmosphere outside by the compressor body 87, itself, or means forreleasing air, which is arranged in the air supply line 88 (not shown).

When a driver feels drowsiness coming on during driving and the driverpushes on a switch for vibration, electro-magnet 86 is not charged withalternating electricity. At that time, magnetic force is generated insaid electro-magnet 86 intermittently in a short pitch, wherein ironcore 83 is attracted toward the position where electro-magnet 86 isinstalled (i.e., toward the right, as shown in FIG. 16). Therefore, thevalve rod 82 moves against elastic force of the spring 89, and, as shownin FIG. 17, the communication of the line 78 and the passage toatmosphere 90 is cut off by maximum diameter part 82a and line 78 andthe passage to air supply line 88 are connected through chamber 85. Air,at air pressure of 3-5 kgs, is force from compressor 87 into a lowerchamber 76. Piston 73 (the area receiving the pressure is 20 cm²) risesand the driver's seat 1 rises together. In the condition that magneticforce is not generated in electro-magnet 86, as mentioned above, becauseline 78 and the passage to atmosphere 90 are connected, the air in thelower chamber 76 is connected with the outside atmosphere, FIG. 16, thepiston 73 is pressed downward by the energy of the spring 77 and alsothe driver's seat lowers. The above-described raising and lowering ofthe driver's seat 1, is repeated, while the switch for vibration ispressed. In this way, if a driver feels drowsiness, the driver canvibrate the driver's seat 1 by repeating rise and fall of such driver'sseat by operating the switch for vibration installed in the controlpanel 18. Therefore, the driver remains alert, does not doze off duringdriving, and traffic accidents caused by dozing during driving can beprevented.

In the seventh embodiment of the invention shown in FIG. 18, means forreleasing air from compressor 87 into the atmosphere outside isinstalled in the channel control valve 91. This means that in thechannel control valve 91 of this embodiment, as shown in FIG. 18, themaximum diameter parts of 92a and 92b of valve rod 92, are formed at thedefinite distance between them in the valve rod 92, whereby the casing93 is divided, respectively, into a right chamber 95, a middle chamber96 and a left chamber 97. Also, a line for releasing force fed air 94 isarranged in the casing 93, whose end opens to the outside of theautomobile through a hole (not shown in Figures) formed in the floor 16of the automobile 15, FIG. 3, into the atmosphere outside. The otherparts, except for these parts, are the same as those of the aboveExample 6 and the same numbering is adopted.

According to the seventh embodiment, the connected line 78 and the airsupply line 88 are connected through the middle chamber 96 when magneticforce is generated in electro-magnet 86, as shown in FIG. 18. Theconnected line 78 and the line for the passage to the atmosphere 90 areconnected through the right chamber 95, while the air supply line 88 andthe line for releasing force feed air 94 are connected through themiddle chamber 96 when magnetic force is not generated in electro-magnet86, as shown in FIG. 19. Thus when the compressor 87 is driving, the airpressed by compressor 87 is not sent to the lower chamber 76 of thecylinder chamber 74 so that the air can be discharged to outside of theautomobile.

In the embodiments, the combination of the valve rod 82 (92) combinedwith the spring 89 are adopted for the channel control valve 80 and 91.However, a rotary valve type is also acceptable.

In the eighth embodiment of FIG. 20, the driver's seat 1 is vibrated bya hydraulic cylinder. More particularly, in hydraulic cylinder 120, aT-shaped piston rod 123 slides vertically. The driver's seat is fixed ona supporting part of the seat 123a formed at the upper end of piston rod123. The cylinder chamber has a pressure chamber 126 formed betweenupper and lower hydraulic packings 122a and 122b, respectively.Pressured chamber 126 is divided into an upper pressure chamber 124 anda lower pressure chamber 125 by a maximum diameter part 123b formed onpiston rod 123.

In servo valve 101, pilot stage 102 and power stage 103 are formed; andfirst valve rod 104 is arranged vertical-sliding-freely in the pilotstage 102, while the second valve rod 105 is arrangedvertical-sliding-freely in the power stage 103. Pilot stage 102 isconnected through fifth line 106 to an upper part of power stage 103,and through sixth line 107 to a lower part of power stage 103. Powerstage 102 is connected through the first line 127 to an upper pressurechamber 124 of the cylinder chamber and through the second line 128 to alower pressure chamber 125, through third line 113 to a hydraulic pump,not shown, and through fourth line 115 to first line for returning oil114, respectively. A vibration generator, by dynamic electricity 108, isarranged under pilot stage 102. Coil 108a is positioned inside itsvibration generator by dynamic electricity 108 while controlled body 110is energized, upward, by a spring 109 in the upper part of the vibrationgenerator 108. Coil 108a is, as in the fourth embodiment, electricallyconnected through an inverter with the battery 17 of the automobile 15,FIG. 3. Electricity supplied from the inverter to the coil 108a isconverted into alternating current. An on-off switch, not shown,controls electric supply to coil 108a and is installed in the controlpanel 18, so that the controlled body 110 can be controlledvertical-sliding-freely by sending alternating current to coil 108a.Since controlled body 110 contacts first valve rod 104, the first valverod 104 is energized upward. Additionally first valve rod 104 isenergized upward by an extension spring 111 fixed on the upper part ofthe pilot stage 102. The first displacement transducer 112, whichdetects a displacement in the lower part 105a of the second valve rod105, is installed in the lower part of the power stage 103. Thedetection signal is sent to the vibration generator by dynamicelectricity 108 as feedback. On the other hand, the second displacementtransducer 129, which detects displacement in the lower part 123c ofpiston rod 123, is installed in the lower part of cylinder chamber 126.Such detection signal is sent to the vibration generator by dynamicelectricity 108 as feedback. In FIG. 20, reference 116 is the secondline for returning oil 117 is the seventh line connected with thehydraulic pump and 118 is a diaphragm, which are installed in the oiltight condition, on the controlled body 110 and the vibration generatorby dynamic electricity 108.

In the above structure, when alternating current is sent to the coil108a of the vibration generator by dynamic electricity 108 so that thecontrolled body is moved upward, as shown in FIG. 21, the first valverod 104 moves upward and the seventh line 117 is connected with thesixth line 107 so that oil force fed by the hydraulic pump is suppliedfrom the lower end of the power stage 103 to inside the power stage 103.At that time, the second line for returning oil 116 and the fifth line106 are connected so that oil is returned from the upper end of thepower stage 103 to a tank (not shown in Figures). Thus the second valverod 105 moves upward and, as a result, the third line 113 is connectedwith the second line 128 so that the oil from the hydraulic pump issupplied to the lower pressure chamber 125. The first line for returningoil 114 and the first line 127 are connected through the fourth line 115so that oil is returned from the pressure chamber 124 to the tank.Thereby, piston rod 123 is moved upward and the driver's seat 1 rises.When the controlled body 110 is moved downward, in an opposite reactionagainst the above, the piston rod 123 is moved downward so that thedriver's seat falls. Thus, in addition to the vertical movement of thecontrolled body 110, the driver's seat 1 vibrates. In this case, theamount of inflow oil and outflow oil to a lower pressure chamber 125 oran upper pressure chamber 124, changes by the displacement of the firstvalve rod 104 in the pilot stage 102, so that the piston rod 123vibrates at a speed in proportion to the oil flow. The detection signalsfrom the first displacement transducer 112 and the second displacementtransducer 129 are sent to the vibration generator by dynamicelectricity 108 as feedback, which enables precise control.

In the eighth embodiment, if a driver feels drowsiness coming on, thedriver can operate switches installed on a control panel (such as,control panel 14 as shown in FIG. 6), whereby alternating current issent into the coil 108a of vibration generator by dynamic electricity108 so that a servo valve 101 operates to supply oil from the hydraulicpump to the pressure chambers 124 and 125 of the hydraulic cylinder 120and the piston rod 123 moves vertically and the driver is kept alert andtraffic accidents will be prevented.

In the ninth embodiment in FIG. 22, the vibration generator 132, bydynamic electricity 130, is adapted to vibrate the driver's seat 1. Indetail, support axes 133 of the vibration generator, by dynamicelectricity 130, are extended from opposite sides in a horizontaldirection, and supported by support base, not shown. And also, in thevibration generator by dynamic electricity 130, a base 135, wherein thedriver's seat is fixed, is supported by iron core 134. The iron core 134has an annular body magnetic pole 136, an annular upper yoke 137 fixedon an upper part of annular body magnetic pole 136, an annular loweryoke 138 fixed on a lower part of body magnetic pole 136, an annularupper center magnetic pole 139 and a lower center magnetic pole 140,arranged concentrically. Annular exciting coils 143 and 144 are arrangedconcentrically in two divided spaces of upper annular chamber 141 andlower annular chamber 142 formed thereby. Both exciting coils 143 and144 are, like in embodiment four, electrically connected with thebattery 17 of the automobile 15 so that the battery supplies directcurrent to both exciting coils 143 and 144.

An annular cavity 145, connecting the spaces of upper chamber 141 andlower chamber 142, is formed concentrically with exciting coils 143 and144 in a central annular projecting portion 136a of body magnetic pole136, while a bore 146 is formed through the center of upper centermagnetic pole 139. Linear ball bearing 149 is fixed on the upper part ofpit 146. A connecting holes 151, connecting with upper space 141, areformed at regular intervals in upper yoke 137. A hole of small diameteris formed on the upper portion of lower center magnetic pole 140, and ahole of larger diameter is formed under the hole of small diameter.Linear ball bearing 147 is fixed in the small diameter while air spring148 is positioned in the hole of larger diameter.

Supporting rod 150, which extends downward from the center of theunderside of base 135, passes through bore 146 of upper center magneticpole 139 and the hole of small diameter of lower center magnetic pole140 and is supported by air spring 148, for freevertical-sliding-movement by linear ball bearings 147 and 149.Connecting piece 152 extends downward through connecting hole 151 on thelower part of base 135, and is connected, through connecting hole 151,with annular driving coil 153. Driving coils 153, 163 are arranged inthe cavity concentrically with concentric exciting coils 143 and 144,and 141 and 142 respectively. Driving coil 153 is electricallyconnected, through an inverter, with battery 17, whereby electricity,supplied to the driving coils 153, 163 is converted into alternatingcurrent. An on-off switch, not shown, controls the supply of electricityto driving coil 153 and is arranged in a control panel, such as controlpanel 14 as shown in FIG. 6. In FIG. 22, reference number 154 is an airseal and reference number 155 is a loop spring, which works as a baffle.

In the ninth embodiment, when the switch of the control panel is turnedon, direct current is charged through exciting coils 143 and 144; andmagnetic flux in the direction of arrow A is formed and alternatingcurrent is charged through the driving coil 153 at right angles to themagnetic flux of the direct current in coils 143, 144. According toFleming's rule, an excitation force works in the B arrow directions, andthe driver's seat vibrates. Therefore, if a driver feels drowsinesscoming on, the driver can vibrate the driver's seat 1 by turning on theswitch; thereby preventing dozing of the driver during driving whichsubsequently prevents accidents from occurring.

In each of the above embodiments, the switch to turn on/off supply ofelectric current to vibration motor 10, electro-magnet 43, 86 or coil108a, 153 is installed in operation panel (or control panel) so that thevibration motor 10 operates by turning on the switch if a driver feelsdrowsiness. This is not construed to limit the scope of this invention.For example, instead of said switch, a timer, installed in the operationpanel (or control panel), is a adoptable. In such a case, only if thetimer is set up in starting off, the vibration motor 10 or the likeoperates when a certain time (for example, 10 minutes) has pass, whileit also stops automatically when a certain time (for example, 5 minutes)has pass since it started to move. Such a timer is convenient in casethat a person knows in advance from experience that he will feeldrowsiness at a certain time (for example, 10 minutes) from starting todrive. In addition, instead of the timer for moving/stopping thevibration motor or the like, the switch for moving/stopping thevibration motor 10 or the like can be adoptable together with the timerso as to operate manually.

Thus, according to this invention, a driver's seat having a vibrationgenerator connected to the driver's seat and controls for turning thevibration generator on and off for vibrating the driver's seat so thatwhen a driver feels drowsiness coming on, the driver can operate thecontrols for switching on-off the vibration generator so that thedriver's seat can be vibrated and the dozing of the driver duringdriving can be prevented. Accordingly, occurrences of accidents can beprevented.

While the invention has been particularly shown and described inreference to preferred embodiments thereof, it will be understood bythose skilled in the art that changes in form and details may be madetherein without departing from the spirit and scope of the invention.

What is claimed is:
 1. An apparatus for vibrating a seat comprising adriver's seat, means for vibrating said driver's seat and means forcontrolling vibration of said means for vibrating the driver'sseat,wherein said means for vibrating said seat comprises a rod havingone end sliding-freely in a cylinder chamber and the other end projectedoutward from said cylinder chamber and connected to said driver's seat,a piston connected to said one end of said rod and sliding-freely insaid cylinder chamber, means for supplying pressure fluid to saidcylinder chamber, a channel control valve for supplying and dischargingsaid pressure fluid to said cylinder chamber and means for controllingsaid valve for repeatedly freely sliding said piston.